Tension control device



Oct. 9, 1962 D. JAMES 3,057,578

TENSION CONTROL DEVICE Filed Dec. 5, 1960 3,057,578 Patented Oct. 9, 1962 ice 3,057,578 TENSIQN CUNTRQL DEVICE Donlin James, Madison Township, Montgomery County,

Ohio, assignor, by mesne assignments, to The Dayton Tire 8: Rubber Company, Dayton, Ohio, a corporation of Ohio Filed Dec. 5, 1960, Ser. No. 73,791 4 Claims. (Cl. 242156.2)

This invention relates to an improved tension device, particularly a tension device used for controlling tension of wires fed from a reel or spool. The invention further relates to a method for controlling this tension.

In conjunction with the manufacture of automotive tires it is customary to form a bead which consists of a number of individual wires grouped into a set and then collectively wrapped. In order to group these wires, it is necessary to feed them from a plurality of individual spools and combine them in some manner into the composite bead. Since each of the spools contains wire which has been wound under different conditions of tightness or quantity, combining them creates problems when it is realized that each of these diverse wires must be fed at a constant rate of speed into the finished bead. It is, therefore, highly important that the rate of letotf of the wire from each spool must be carefully controlled. In the prior art this has been accomplished by means of a braking device which is to be applied to or released from the spool in accordance with the pull upon the spool. This is very simply accomplished by merely applying frictional pressure by means of a brake band upon a brake drum which is a part of the letoff spool so that when the wire is being pulled off too fast the brake will clamp down upon the drum and slow the rate of feed of the spool until the proper tension has been again reached, at which time pressure on the drum is relieved. By transmitting wire tension through a mechanism into the brake drum, proper control can be achieved.

In the prior art devices the braking mechanism created certain problems because the brake drums had to be removed before the spool could be removed and replaced. Further, when the spool had payed out to a certain point, the tension had to be adjusted by very complicated procedures through turnbuckles, screw type arms, and the like. Quite often this adjustment took fifteen to twenty minutes and was found to be a considerable nuisance.

Applicants invention consists of improving the brake drum and the braking mechanism so that not only can the brake be more easily removed but the adjustment can be accomplished in a matter of thirty seconds instead of the fifteen to twenty minutes previously required.

It is a primary object of this invention, therefore, to provide an improved brake tensioning device for a wire letofi spool.

It is a further object of the invention to provide an improved adjustment device for the brake mechanism.

It is still another object of the invention to provide a brake device which can be quickly removed to permit replacement of the spool.

These and other objects of the invention will be more fully described in the following specification, in which:

FIGURE 1 is a perspective view of the entire bead letoif mechanism.

FIGURE 2 is a side elevation illustrating the braking mechanism which is the principal part of this invention.

FIGURE 3 is an enlarged longitudinal sectional view of the braking mechanism of FIGURE 2.

FIGURE 4 is an exploded perspective view of a portion of the mechanism illustrating further details of the invention.

Turning now to FIGURE 1 of the drawings, a conventional bead letoif mechanism is illustrated consisting of a framework generally designated by reference numeral 11, upon which is mounted a spool or reel 12 from which is fed the bead wire 13. Rotatably mounted between the sides of the frame 11 is a shaft 14 upon which is fixed a guide pulley 15 over which the bead wire 13 is passed as it is pulled off the spool. Also rotatably mounted on the frame 11 is another shaft 16 to which is fixedly mounted a pair of arms '17 and 18 supporting another rotatable shaft 19 upon which is fixedly mounted another guide pulley 20. As is readily seen in FIGURE 1, the bead wire after passing over the pulley 14 then passes under the pulley 20, then on to the rest of the bead assembling machine which is not shown as it has no bearing on the present invention. Rigidly mounted on one end of the shaft 16 is link 21, which is rotatably attached to another arm 22 which in turn is rockably mounted upon a link 23. By means of a number of apertures 23a mounted in the link 23, the arm 22 may be attached by means of mounting bolts or the like at varying distances.

The portion of the mechanism described above is conventional but that portion which is about to be described, and is better illustrated in FIGURES 2, 3 and 4, comprises the subject matter of my invention. The link 23 terminates in a yoke having two spaced, parallel arms 24 and 25 having rounded ends 26 and 27 with apertures 28 and 29 therein. Loosely mounted upon the upper surface of the yoke arms 24 and 25 is a pressure block 30 which extends across the upper surface of the yoke arms but has a downwardly extending portion 31 which extends between the inner surfaces of these yoke arms. A linkage member or arm 32 is adapted to fit between the inner surfaces of .ends 26 and 27 of the yoke arms 24 and 25, and has a downwardly extending boss 33 having an aperture 34 therethrough which aligns with the apertures 28 and 29. At one end of the member 32 is another aperture 35 passing therethrough, this aperture being threaded to allow the insertion of the adjusting screw 36 which first passes through the lock nut 37 that fits on the upper surface of the member 32. As can thus be seen in FIGURE 3, the inner end of the adjusting screw 36 bears against the upper portion of the block 30. The parts referred to above are assembled together by placing a bearing sleeve 38 upon a shaft 39 which is rigidly mounted to one wall of the frame 11. The boss 33 of the member 32 is then placed between the rounded ends 26 and 27 of the yoke arms 24 and 25 and this subassembly is slipped over the bearing sleeve onto the shaft 39 thus rotatably mounting the member 32 between the yoke arms. In order to lock these members in place, a Washer 40 is placed on the opposite end of the shaft 39 and a locking device such as a cotter pin 41 is passed through a suitable aperture in the end of the shaft.

At one end of the connecting member 32 is a downwardly curved portion 42 which hooks into a brake band attaching member 43 which is permanently fastened to a brake band 44. This brake band is pinned at its opposite end to the frame 11 by means of a suitable attaching member 45 so that it is permanently fastened at that end while coupled into the linkage mechanism by means of its other end 43 with the member 32. The brake drum 46 is mounted on one end of the shaft 47 by means of a set screw 48, outside the framework, this shaft 47 being the same shaft that is a part of the spool or reel 12. It is thus obvious that a braking mechanism is established by means of the linkage to the brake band and the drum.

Operation of the Device Assuming that the spool illustrated in FIGURE 1 has just been emptied and must be replenished, it is first necessary to free the brake drum and brake band so that the spool can be removed from its position within a the frame. The present mechanism permits this to be very simply done by first pulling out the loosely mounted block 30, which then allows the entire linkage member 32 to be rotated freely about the bearing sleeve 38 and between the yoke arms 24 and 25. This, of course, releases the curved end 42 of the connecting member from the member 43 of the brake band, and thus allows the brake band to be swung free from around the drum. By means of the set screw 48, the drum 46 can be slipped oif the shaft 47 and the entire spool 12 with its shaft 47 then removed from within the framework. A new spool is now inserted and the drum 46 again slipped on the new shaft 47, the brake band 44 wrapped around the drum, and the end 42 of the member 32 again slipped into the member 43. By once again sliding the block 30 into place as shown, the linkage is again completed in a matter of a few seconds.

When during the course of feeding the bead wire from the spool it has been determined that the tension has changed, it is only necessary to rotate the adjusting screw 36 and manipulate the lock nut 37 to cause the left-hand end 32a of the member 32 to be raised or lowered with respect to the block 30 and, therefore, with the link 23. When this is done the motion is naturally transmitted to the opposite end 42 of the member 32 and causes the member to rotate about the bearing sleeve 38. This in turn causes either a tightening or loosening of the brake band around the drum 46. It is obvious, for example, that if it is desired to increase the tension on the drum 46 the end 42 must be swung down and, therefore, the end 32a must be swung up, which means that the adjusting screw 36 must be turned clockwise to force it against the block 30.

It is understood, of course, that during the operation of the letoff machine that the tension changes in the wire 13 are transmitted through the pulley 20 and then through members 19, 17, 18, 16, 21, 22, and 23, into the linkage described above to either increase or decrease the tension on the brake drum. This feature of the device, of course, is not a part of the novel structure. Applicants improvement lies in the use of the members consisting of the bifurcated link 23, the block 30, the arm 32, and the adjustment screw 36 to provide a simple change in tensioning and a more easily removed brake band when it is necessary to make a change in the spool.

While a specific form of the invention has been shown in the embodiment illustrated in the drawings, other modifications may be made without departing from the scope of the invention.

I claim:

1. In a tension control device for wire wound on a spool, including wire-contacting means, a brake drum mounted on said spool, a brake band around said drum, and a linkage for transmitting tension of said wire to said brake band to control rate of feed of said wire; the improvement comprising a link having a yoke composed of two spaced, parallel arms as a portion of said linkage, a block across the upper surfaces of said yoke arms, a linkage member rotatably mounted between said yoke arms and supported at one .end by said block and connected at its other end to said brake band, and an adjusting screw mounted in one end of said member to contact said support block in order to provide rotatable adjustment of said member and a corresponding adjustment of said brake band relative to said brake drum.

2. In a tension control device for wire wound on a spool, including wire-contacting means, a brake drum mounted on said spool, a brake band around said drum, and a linkage for transmitting tension of said wire to said brake band to control rate of feed of said wire; the improvement comprising a link having a yoke composed of two spaced, parallel arms as a portion of said linkage, a support block mounted on the upper surfaces of said yoke arms, a linkage member having a straight and a curved end rotatably mounted between said yoke arms and having its straight end supported by said block and its curved end connected to said brake band, an adjusting screw mounted in the straight end of said member to contact said support block in order to provide rotatable adjustment of said member and a corresponding adjustment of said brake band relative to said brake drum, said support block removable to permit rotation of said linkage member out of connection with said brake band to free said brake drum and permit removal of said spool.

33. In a tension control device for cord including cordcontacting means and a brake mechanism responsive to said means for controlling the rate of feed of said cord, the improvement comprising a supporting link activated by said cord-contacting means, an arm pivotally mounted on said link, a pressure block on said link, means at one end of said arm engaging said brake mechanism, and means at the other end of said arm bearing on said pressure block to limit pivotal motion of said arm and to adjust said arm with respect to said pressure block, to create a resulting adjustment in said brake mechanism.

4. The device of claim 3, wherein said pressure block is removable for pivotal release of said arm from said brake mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 1,468,351 Ayres Sept. 18, 1923 1,828,918 Balthasar Oct. 27, 1931 2,215,651 Pierce Sept. 24, 1940 

